The Flow Cytometry Facility of the Fred Hutchinson Cancer Research Center (FHCRC) respectfully requests funds to acquire a Becton Dickinson FACSAria cell sorter to replace an eleven-year-old Becton Dickinson FACS Vantage SE cell sorter. The FACSAria will be equipped with 15 parameter detection, Automated Cell Deposition Unit (ACDU), computer, Aerosol Management System, and table. While the FACS Vantage has been a dependable cell sorter, its limitations have impeded its ability to meet the needs of today's more advanced experimentation. The core user group for the FACSAria consists of members from the major scientific divisions within the FHCRC. As will be noted in the research plan, many of the projects from our varied client base will benefit from the added capabilities of this instrument. These projects will see an immediate enhancement in the research currently being performed due to the FACSAria's heightened sensitivity, its 15-parameter detection, higher throughput, and its ability to sort four populations simultaneously. With the fixed alignment and canned cleaning functions inherent in the instruments design, the FACSAria will benefit the overall functionality of the core facility. The Flow Cytometry facility has operated as a shared resource at the FHCRC for 26 years. It has grown to be an integral part of the scientific research supporting 79 laboratories from 13 programs within the cancer center. With the broad base of applications being run on the facility's cell sorters, the FACSAria would benefit most applications within this shared environment. The FACSAria will address both immediate and future needs of our user community, supporting NIH funded research at the FHCRC.